UC Santa Barbara

Rapid development of the Si photonics industry and its applications in data communication calls for the making of on-chip light sources integrated on the Silicon-on-Insulator (SOI) platform for mass production. Monolithic integration of III-V lasers, especially quantum dot (QD) lasers has gained increasing attention as a key technology to realize efficient, cost-effective, industrial-scale integration of light sources for Si photonics.

In this thesis, we demonstrate for the first time, QD lasers grown and fabricated for electrically pumped lasing both on a planar template and in-pocket-template on 300 mm Si wafers. O-band edge-emitting in-pocket lasers are fabricated on Si with robust performance of continuous wave lasing up to 60 \textdegree C, a maximum double-sided output power of 124.8 mW at 20 °C and high fabrication yield. We also demonstrate for the first time, on-chip etched-facet lasers directly butt-coupled to SiN waveguides made on a 300-mm scale foundry-processed Si photonics wafer, characterized with fiber-coupling from on-chip edge couplers at waveguide output. Process developments addressing issues such as polycrystal deposition on surface, high aspect-ratio pocket geometry, and complications on growth interface affecting coupling are established.

Perspectives on scaling this QD laser process on a 300 mm scale in a Si photonics foundry is also discussed, including remaining challenges of improving laser performance and yield, and prospects on the implementation of fully monolithic integration with a III-V/Si co-processing foundry.